Crown closure cap



Jan. 20, 1970 vy vy w o ET AL 3,490,635

CROWN CLOSURE CAP Filed Oct. 30, 1967 s She et sshe ec '1 FIG. 1 FIG. 2

PATENT AGENT 0,1970 WI.W.-WILSON ETAL 3,490,635,

CROWN CLOSURE CAP Filed Oct. 30, 1967 T 5 SheetPS eQy-Z' ilfi kk FIG. 8

M 4/45 [4? a d/(4 INVENTORS PATENT AGENT Jan. 20, 1970 w. w. WILSON- ET-AL 3,490,635

cnowu CLOSURE CAP Filed Oct 30, 1967 s Sheets-Sheet z I I, (a-Iv v 650x54 INVENTORJ PATE NT AGENT United States Patent 3,490,635 CROWN CLOSURE CAP Wilfred W. Wilson and Alan H. Frankel, Toronto,

Ontario, Canada, assignors to Antocrown Corporation Limited, Weston, Ontario, Canada Filed Oct. 30, 1967, Ser. No. 679,004 Claims priority, application Great Britain, June 19, 1967, 28,225/ 67 Int. Cl. B65d 41/12 US. Cl. 215-39 14 Claims ABSTRACT OF THE DISCLOSURE A crown cap having a cover portion and a skirt portion, the latter having a plurality of spaced apart outwardly extending ribs formed therein and extending from the free edge of the skirt portion towards the cover portion is constructed so that at the free edge the ribs and the parts of the skirt portion joining adjacent ones of the ribs are shaped in a substantially sinusoidal waveform, while other portions of the ribs closer to the cover portion are substantially V-shaped. In another embodiment a reinforcing member is formed integral with each of the ribs and is disposed intermediate the ends of the ribs.

This invention relates to improved crown caps and methods and apparatus for making the same.

A crown cap is a known form of closure for bottles and the like, and it consists generally of a sheet metal stamping or pressing having a cover portion or closure wall, which usually is of circular form, and a skirt portion formed integral therewith depending from the cover portion. The skirt portion is formed with a plurality of ribs or corrugations. In the past, the parts of these ribs nearest the cover portion have been generally rounded in cross-section, while the parts of the ribs adjacent the free edge of the skirt portion have been substantially V- shaped. Since the parts of the skirt portion joining adjacent ones of the ribs have been generally flat, this has meant that the aforementioned free edge has had a substantially rectangular waveform with inclined leading and trailing edges, while a cross-section taken through the ribs and the parts of the skirt joining adjacent ones of the ribs at a point close to the cover portion would reveal spaced apart substantially one-half sine wave projections separated from each other by substantially flat sections. As manufactured, the skirt portion of the cap is outwardly flared in a direction away from the cover portion, and the cap, when it is applied to, for example, the neck of a bottle to close the bottle, is so operated on that the skirt portion adjacent to the free edge thereof is crimped under a circumferential lip which is presented by the neck of the bottlei This crimping action is performed by an operation which is known in the trade as wiping.

A crown cap which is applied to the neck of a bottle in the above-described manner usually is removed, when it is desired to remove some or all of the bottle contents from the bottle, by means of an opener device which utilizes the lever principle to remove the cap from the bottle. Once removed from the bottle, the cap cannot be used to re-seal the bottle. To overcome this disadvantage, it has been proposed recently to form, for example, the neck of the bottle with a series of part helical threads, instead of the aforementioned circumferential lip, so that when the cap is wiped onto the neck of the bottle, a series of corresponding and mating part helical grooves are formed in the skirt portion of the cap, thereby permitting the cap, as an alternative "ice to being removed by means of an opener as hereinbefore described, to be removed by being unscrewed from the bottle, in which case the cap can be used subsequently to re-seal the bottle. As will be understood, the latter arrangement is of primary value in cases in which only a portion of the bottle contents are intended to be removed from the bottle at any one time.

It should be emphasized that irrespective of which of the above arrangements is used to apply the cap to, for example, the neck of a bottle, the form of the cap as manufactured is the same, and the present invention, although especially applicable where the cap is intended subsequently to be used in the aforementioned screw manner, is concerned with a crown cap irrespective of the manner in which the cap is intended subsequently to be applied, since it is a primary object of this invention to provide a crown cap having a skirt portion that crimps evenly during wiping, thereby minimizing the possibility of fracturing the glass threads or circumferential lip formed on the neck of a bottle being capped either during the wiping operation or subsequently when the cap is being removed, if it should be removed by being lifted rather than unscrewed.

In a preferred embodiment of this invention, the free edge of the skirt portion is so formed that the risk of injury or damage being caused by this free edge is substantially eliminated. In this respect in many crown caps as hitherto manufactured the free edge of the skirt portion of each cap has been constituted by a raw metal edge which is liable to cause injury to persons who may handle the cap either before or after the cap has been applied to a bottle, and which is liable to cause damage to, for example, personal clothing which comes into contact with the cap. Furthermore, the free edges of the skirt portions of such caps may become interengaged, for example, when the caps are disposed within a hopper prior to being applied to bottles, owing to the roughness of the free edges, thereby preventing the free flow of the caps as individual elements from the hopper to, say, a bottle capping machine.

Since crown caps which are intended to the aforementioned screw manner must be a person when being removed from the neck of a bottle by being unscrewed therefrom, one reason for the preferred embodiment of the present invention being of particular, although not exclusive importance, when the cap is intended to be used in this screw manner, will readily be appreciated.

A crown cap according to one embodiment of the present invention comprises a cover portion, which is adapted directly or indirectly to seal an aperture in a container, and a skirt portion which depends from the cover and has a free edge remote from the cover portion. The skirt portion has a plurality of spaced apart, outwardly extending ribs formed therein extending from the free edge of the skirt portion towards the cover portion of the cap. The ribs at the free edge and the parts of the skirt portion at the free edge that join adjacent ones of the ribs are shaped in a substantially sinusoidal waveform, while second parts of the ribs remote from the free edge and closer to the cover portion are substantially V-shaped.

In another embodiment in which the ribs and the parts of the skirt portion joining adjacent ribs preferably are shaped as outlined in the preceding paragraph, although this is not essential, and to this end, the ribs and joining parts may be in prior art or other configurations, each rib includes a reinforcing member formed integral with the rib and disposed between the be used in pp y cover portion of the cap and the free edge of the skirt' portion.

In a preferred embodiment of this invention there is provided a crown cap constructed as outlined in either or both of the preceding paragraphs in which the skirt portion is turned, preferably inwardly, upon itself at the free edge of the skirt portion.

The curled bead constituting the free edge of the skirt portion may be in the form of a reflex bend formed in the skirt portion.

The outer surface of the curled bead is preferably constituted by a portion of the outer surface of the skirt portion, i.e., the skirt portion is turned inwardly, thereby facilitating the subsequent wiping of the cap, as is explained hereinafter.

In the manufacture of a crown cap embodying this invention, new and useful apparatus is employed at one stage and this apparatus also may be used in the forming of prior art and other types of crown caps. This apparatus includes a male die member made of a deformable material and a cage which cooperates with the female die member to define a space surrounding the male die member and to limit the extent to which the male die member can deform in certain directions.

In order that the invention may be more clearly understood and more readily carried into effect, the same will now be described more fully with reference to the accompanying drawings in which:

FIGURES 1 to 4 inclusive are side views in section showing a crown cap embodying this invention at each four stages in the manufacture thereof, FIGURE 1 showing the cap in the form of a blank, and FIGURE 4 showing the fully manufactured cap;

FIGURES 5 to 7 inclusive are sectional views along the longitudinal axes of three sets of dies used in the manufacture of the crown cap, FIGURES 5, 6 and 7 showing the sets of dies used to form the cap into the configurations illustrated in FIGURES 2, 3 and 4 respectively;

FIGURE 8 is a side view of a crown cap constituting a preferred embodiment of this invention and piror to the cap being wiped on to the neck of a bottle;

FIGURE 9 is a more detailed view of two of the ribs of the cap of FIGURE 8;

FIGURE 10 is a section taken along line 10-10 in FIGURE 8;

FIGURE 11 is a view looking directly at a part of the free edge of the skirt portion of the cap of FIGURE 8; and

FIGURE 12 is a sectional view showing the neck of a bottle with a crown cap embodying this invention seated thereon and a wiper for wiping the crown cap on to the bottle neck.

With reference to FIGURE 8, there is shown a crown cap 100 constituting a preferred embodiment of this invention and consisting of a sheet metal stamping or pressing having a cover portion 51 and a skirt portion 102 formed integral with the cover portion and depending downwardly therefrom. Cover portion 51 is generally circular in plan and may be fiat or bowed slightly upwardly. The part 52 of skirt portion 102 closest to cover portion 51 is slightly outwardly flared in a direction away from cover portion 51 while the part 53 of skirt portion 102 closest to the free edge 103 thereof is even more outwardly flared. Provided in skirt portion 102 are a plurality of regularly spaced apart, outwardly extending ribs or corrugations '62 that commence at free edge 103 and terminate just short of cover portion 51. Ribs 62 are widest at free edge 103 and taper to their narrowest width adjacent cover portion 51.

An important feature of a crown cap constituting one embodiment of this invention is the shaping of the ribs and the parts of skirt portion 102 that join the ribs both at free edge 103 of the skirt portion and at a point remote from free edge 103 and closer to cover portion 51. This shaping is best shown in FIGURES 10 and 11. Thus, as seen in FIGURE 11, at free edge 103, ribs 62 and the parts of skirt portion 102 joining adjacent ribs are shaped in a substantially sinusoidal waveform. As may be seen by reference to FIGURE 10, at a point closer to cover portion 51, ribs 62 are substantially V-shaped, the ribs at this point having two relatively flat sides 105 and 106 inclined towards each other and each terminating along a substantially straight line 107. As also seen in FIGURE 10, the parts of skirt portion 102 joining adjacent ones of ribs 62 at a point remote from free edge 103 and closer to cover portion 51 are substantially flat. This is a preferred embodiment of the invention, although not essential to the invention, and these parts of skirt portion 102 may be curved slightly outwardly if desired. When these parts are flat, however, it will be noted that ribs 62 and the parts of skirt portion 102 joining the same adjacent cover portion 51 are shaped in a substantially rectangular waveform having inclined leading and trailing edges 105 and 106.

As shown in FIGURES 8 and 9, a crown cap constituting another embodiment of this invention preferably has a reinforcing member 108 formed integral with each of the ribs and disposed intermediate free edge 103 and the opposite ends of the ribs. While it is preferred that these reinforcing members 108 be employed with a crown cap having ribs and intermediate joining skirt parts configured as hereinbefore described and shown in FIGURES 8, 10 and 11, it is to be understood that reinforcing members 108 may be employed with crown caps having differently configured ribs and intermediate joining skirt parts. The shape of reinforcing members 108 may vary, but preferably they are curved outwardly in directions both parallel to and perpendicular to the longitudinal axes of the respective ones of the ribs with which the reinforcing members are integrally formed. Preferably reinforcing members 108 are substantially part spherical in configuration.

As shown in FIGURES 8 and 9, in a preferred embodiment of this invention, skirt portion 102 is turned inwardly upon itself at free edge 103 to form a bead 58, thereby avoiding having free edge 103 constituted by What may be a relatively sharp, raw metal edge 109. It is possible to have skirt portion 102 turned outwardly upon itself to achieve the same end, but this is a less desirable alternative, since raw metal edge 109 then would lie against the outside surface of cap 100, rather than against the inside surface thereof.

It should be noted that the configuration of ribs 62 and the parts of skirt portion 102 that join the adjacent ones of the ribs is substantially the same as shown in FIGURE 11 at all points between free edge '103 and reinforcing members 108, while the configuration shown in FIGURE 10 is the same at all points between reinforcing members 108 and the ends of ribs 62 closest to cover portion 51.

The crown cap of FIGURE 8 is shown in uncrimped form, i.e. in the form it would have prior to being wiped on to the neck of a bottle.

Referring to FIGURE 12, there is shown the neck 110 of a bottle having a crown cap 100 of the type shown in FIGURE 8 seated thereon with cover portion 51 bridging the opening of the bottle. As shown in FIGURE 12, crown cap 100 may be provided on the undersurface thereof at least in the area directly above neck 110 with any conventional sealing material 111. This may be a cork disc, for example. It also will be noted that neck 110 has glass threads 112 formed thereon, although these could be replaced with a single circumferential glass lip.

Also shown in FIGURE 12. is a wiper 113 in the form of a hollow metal cylinder having an outwardly flared, inner, leading surface 114. The operating mechanism for wiper 113 is not shown, as it may be conventional in nature, and, in any event, forms no part of the instant invention. It will be understood, however, that, in operation, wiper 113 is moved downwardly in the direction of the arrow, crimping crown cap 100 and forming grooves in skirt portion 102 thereof as a result of the pressing of skirt portion 102 against glass threads 112. After this has been done, wiper 113 is retracted leaving a sealed bottle with a threaded screw cap of the crown type.

The shaping of ribs 62 and the parts of skirt portion 102 joining adjacent ribs as shown in FIGURES and 11 is of considerable importance in ensuring an overall even crimp. In this respect, if the parts of ribs 62 that are disposed between reinforcing members 108 and cover portion 51 were smoothly curved, as has been the case in the past, an even crimp will not be obtained during the wiping operation, and some of the ribs will collapse to a considerably greater extent than other ones of the ribs. This often results in breakage of the relatively small glass threads on the neck of the bottle. Of course, this is very undesirable, since it not only makes the cap diflicult to remove from the neck of the bottle, but also the contents of the bottle may become contaminated with broken glass. Even if the glass threads or circumferential glass lip, as the case may be, on the neck of the bottle were not broken during the wiping operation, uneven crimping can lead to breakage during removal of the cap with a conventional opener.

Reinforcing members 108 also assist in obtaining even crimping during wiping by trussing each rib at its most critical area. However, reinforcing members 108 also serve the function of causing the inwardly turned edge of skirt portion 102 to remain clear of threads 112 during the wiping operation, because, at the end of the wiping cycle, compression forces exerted by wiper 113 bear on reinforcing members 108, rather than on the inwardly turned edge of skirt portion 102. The sinusoidal waveform shown in FIGURE 11 also assists in keeping the inwardly turned edge clear of threads 112, because, during the wiping operation, the substantially V-shaped portions of ribs 62 are more readily forced into the bottle finish than the sinusoidal portions of the ribs, since the sinusoidal portions permit more shrinkage and loss of metal. Thus there is less possibility of any one rib shrinking to a suflicient extent more than the others that the curled edge of the cap might be brought beneath thread 112 at any point.

The method and apparatus employed in the manufacture of crown caps embodying this invention now will be described with reference to FIGURES 5, 6 and 7. In these figures 10a, 10b, 10c denote upper die blocks illustrated in FIGURES S, 6 and 7 respectively. 11a, 11b, and 110 denote lower die blocks shown in FIGURES 5, 6 and 7 respectively.

12a, 12b and 120 denote the upper die members of the sets of dies shown in FIGURES 5, 6 and 7 respectively, the die member 12a being disposed within a hollow, cylindrical member 13, the upper end of which has an inwardly directed annular flange 14 which is adapted to abut against annular shoulder 15 on die member 120, thereby to restrict the permitted downward movement of the member 13 relative to die member 12a. Flange 14 is acted upon by a compression spring 16 which urges member 13 in a downward direction relative to die block 10a.

The upper end of die member 12a is formed with a screwthreaded recess 17 with which a screw member 18 is in adjustable engagement. Screw member 18 is provided with a head 19, by means of which screw member 18 may be rotated relative to die member 12a, thereby to adjust the setting of die member 12a relative to the die block 10a.

Small bore passages 20 are formed in die member 120, these passages 20, the purpose of which will be hereinafter explained, interconnecting recess 17 with the interface between die member 12a and member 13, and interconnecting recess 17 with the lower face of die member 12a.

With particular reference to FIGURE 6, die member 12b is of hollow, cylindrical form and has disposed therewithin a locator 21, the upper end of which has an annular flange 22 which is adapted to abut against an annular shoulder 23 on die member 12b thereby to restrict the permitted downward movement of locator 21 relative to die member 12b. A compression spring 24 acts on 10- cator 21 to urge locator 21 in a downward direction relative to die member 12b and die block 10b, the upper end of die member 12b having an annular flange 25 which is in abutting engagement with an annular shoulder 26 on die block 10b, thereby positively locating die member 12b relative to die block 10b. Die member 12b is fixed relative to die block 10b.

Locator 21 has a centrally disposed passage 27 formed therethrough, an ejector pin 28 being disposed within passage 27 and being urged in a downward direction by another compression spring 29. An enlarged head 30 provided on the upper end of ejector pin 28 abuts against a shoulder 31 on locator 21, thereby to restrict the permitted downward travel of ejector pin 28 relative to locator 21.

The upper ends of springs 24 and 29 operatively act against a fixed structure.

With reference to FIGURE 7, die member 12c is constituted by a cylindrical insert 32 fixed in the lower end of a cylindrical metal member 33, and a rigid metallic insert 34 which covers the lower face of insert 32. Insert 32 is formed of a suitable deformable material, e.g.', rubber.

Member 33 and die member 12c are disposed within a substantially cylindrical sleeve 63, the upper end of which has an annular flange 64 which abuts against an annular shoulder 65 on die block 100, thereby to restrict the permitted downward movement of sleeve 63 relative to die block 100. A compression spring 66 acts on flange 64 to urge sleeve 63 in a downward direction relative to member 33 and die member 120, and also relative to die block the upper end of member 33 having an annular flange 35 which is in abutting engagement with an annular shoulder 36 on die block 100, thereby positively locating member 33, and hence also die member 12c, relative to die block 10c. Member 33 is fixed relative to die block 100.

Referring again to all of FIGURES 5, 6 and 7, 37a 37 b and 370 denote, respectively, the lower die members. These die members 37a, 37b and 37c are each of hollow, cylindrical form and have disposed therein cylindrical members 38a, 38b and 38c, respectively, said members being identical and each including at the upper end thereof a recessed housing for a magnet 90, 91 and 92, respectively, the function of which will be described hereinafter in detail. The lower ends of members 38a, 38b and 380 are provided with annular flanges 39a, 39b and 390, respectively, and these are urged in an upward direction into abutting engagement with annular shoulders 40a, 40b and 400, respectively, by compression springs 41a, 41b and 41c, respectively, the shoulders 40a, 40b and 400 being on lower die members 37a, 37b and 370, respectively. The lower ends of springs 41a, 41b and 410 operatively act against a fixed structure.

The lower die members 37a, 37b and 37c present at their lower ends flanges 42a, 42b and 420, respectively, which are in abutting engagement with annular shoulders 43a, 43b and 430, respectively, on lower die blocks 11a, 11b and 11c, respectively, thereby positively locating die members 37a, 37b and 37c relative to die blocks 11a, 11b and 11c, respectively. Die members 37a, 37b and 37c are fixed relative to die blocks 11a, 11b and 110, respectively.

The upper end of lower die member 37a shown in FIGURE 5 is formed with a recess 44 within which a sheet metal blank 45, which is of circular form and which is shown in section in FIGURE 1, is initially located, blank 45 being retained in this location'by means of magnet 90. Upper died block 10a is moved towards lower die block 11a until the lower edge of member 13 contacts the outer edge of blank 45, whereupon continued movement of die block 10a towards die block 11a results in die member 12a contacting blank 45 and pressing blank 45 into the form determined by the relative configurations of the lower face of die member 12a and the upper face of die member 37a. The movement of die block a towards die block 1101 after member 13 contacts the outer edge of blank 45 results in compression of spring 16, while, during the pressing of blank 45, member 38a is urged in a downward direction relative to die member 37a, thereby also compressing spring 41a.

The lower face of die member 12a is formed with a slightly convex portion 46, a short, slightly outwardly flared portion 47 and a portion 48 substantially perpendicular to the longitudinal axis of die member 12a, while the upper face of die member 37a is formed with a short, substantially cylindrical portion 49 and a flared portion 50, so that, as shown in FIGURE 2, the blank 45 is, after the above-described pressing operation, in the form of a member having a circular wall 51, which is of slightly outwardly dished form, together with a skirt portion which is upwardly directed and which extends from the periphery of the wall 51. This skirt portion is constituted by a portion 52 adjacent to the wall 51 and slightly outwardly flared, a portion 53 that is substantially perpendicular to thelongitudinal axes of the member, and a short upper portion 54 of substantially cylindrical form. Air flow through passages ensures that when upper die block 10a is moved away from lower die block 11a, the member being formed from blank 45 will not be retained by a vacuum effect in engagement with the lower face of the die member 12a.

This member is transferred from the set of dies illustrated in FIGURE 5, which constitutes a first forming station, to a second forming station constituted by the set of dies illustrated in FIGURE 6. The member is held at the desired location at the second forming station under the influence of magnet 91. The upper face of die member 37b is formed with a flared portion 55 which corresponds with the flared portion 52 of the member, while the lower face of locator 21 is of slightly convex form and corresponds with the form of the wall 51 of the member, the lower face of die member 12b being formed with a recess 56 having a rounded portion 57. Thus, when upper die block 10b is moved towards lower die block 11b, ejector pin 28 initially contacts wall 51 of the member and is urged in an upward direction relative to locator 21, thereby causing compression of spring 29, After the lower face of locator 21 has contacted wall 51 of the member, continued movement of die block 10b towards die block 10c causes the member to be urged in a downward direction, thereby causing member 38b to be urged in a downward direction relative to die member 37b with resultant compression of spring 41b until flared portion 52 of the member contacts the correspondingly flared portion 55 presented by die member 37b, whereupon upward movement of ejector pin 28 and of locator 21 relative to the die member 12b, with resultant compression of both spring 29 and spring 24, is produced as die block 10b continues to move towards die block 11b. After the upper edge of the portion 54 of the member contacts rounded portion 57, an inwardly directed curled bead or reflex bend 58 (FIG. 3) is progressively formed in the portion 54, the curved surface 57 acting as a curved camming surface during this formation of the head or bend 58.

After the above-described operation has been performed at the second forming station, the member which originated as blank 45, and which now constitutes a partly formed crown cap according to the invention, is as shown in FIGURE 3. The member is removed from the second forming station and is transferred to the third forming station shown in FIGURE 7, the ejector pin 28 ensuring that the member is not retained in engagement with upper die member 12b when die block 1% is moved away from die block 11b.

At the third forming station the member constituting the partly formed cap is held at the desired location by magnet 92. Upper die block is moved towards lower die block until the lower face of die member 120, which is presented by the insert 34, contacts wall 51 of the member. During continued movement of die block 100 towards die block 11c, the member being formed moves in a downward direction relative to die member 37c until flared portion 52 of the member contacts a correspondingly flared portion 61 formed on the upper face of die member 37c. The flared portion 60 above flared portion 61 is corrugated, these corrugations extending in a tapered manner from flared portion 60 part way into flared portion 61, so that as upper die block 10c continues to move towards lower die block 11c, flexible rubber insert 32, which may be formed of any suitable resiliently deformable material, is deformed to cause the skirt portion of the member to be corrugated in a configuration which corresponds with that of the corrugations formed on the upper face of die member 370. During the aforementioned continued movement of upper die block 10c towards lower die block 110, and before insert 32 has been deformed to any substantial extent, the lower edge of the sleeve 63 contacts the upper face of lower die block 110, whereupon, as die block 10c continues to move towards die block 11c, sleeve 63 is urged in an upward direction relative to die block 100, causing compression of spring 66. Since, therefore, sleeve 63 surrounds insert 32 during the major part of the resilient deformation of the insert, sleeve 63 restricts the increase in the radial dimensions of insert 32, or cages the insert, during the deformation thereof, so ensuring that insert 32 exerts a force on the skirt portion of the member which is suflicient to form the corrugations therein. Thus, it will be seen that during the formation of the corrugations, insert 32 is restrained against deformation or expansion in all directions except against the member being formed, and the pressure exerted by insert 32 on the member being formed forces it into the configuration of the forming surface of die member 370.

The manufacture of the crown cap has now been completed, the corrugations in the skirt portion of the cap, Which extend substantially over the full height of the skirt portion of the caps from adjacent to the wall 51 and which, as will be understood, are of tapered form in the portion 52, being indicated at 62 in FIGURE 4.

After removal from the third forming station, the cap may be transferred to, for example, a bottle-capping ma chine at which the skirt portion of the cap is wiped onto the neck of a bottle, thereby to close the bottle although, as will be understood, a sealing gasket first may be disposed or formed on the inner face of the closure wall 51, as is the conventional practice with crown caps.

The transferral of blank 45 to the first forming station shown in FIGURE 5, and also the transferral of the cap in the appropriate stages of manufacture between the first and second forming stations, between the second and third forming stations, and from the third forming station, is preferably performed automatically by a transfer mechanism which forms no part of the present invention and is not therefore described or illustrated.

According to the preferred embodiment of the invention as hereinbefore described, the curled head or reflex bend 58 is inwardly disposed relative to the skirt portion of the cap, so that the outer surface of the head or bend 58 is constituted by part of the outer surface of the skirt portion, the subsequent wiping of the skirt portion of the cap onto the neck of a bottle thereby being facilitated, since the risk of the mechanism which performs the wiping operation jamming upon or deforming the bead or bend 58 is thus reduced to a minimum.

While preferred embodiments of this invention have been disclosed herein, those skilled in the art will appreciate that changes and modifications may be made therein without departing from the spirit and scope of this invention as defined in the appended claims.

What we claim as our invention is:

1. In a crown cap of the type having a cover portion and a skirt portion, said skirt portion having a free edge disposed remote from said cover portion, said skirt portion also having a plurality of spaced apart outwardly extending ribs formed therein and extending from said free edge towards said cover portion, the improvement wherein at said free edge said ribs and parts of said skirt portion joining adjacent ones of said ribs are shaped in a substantially sinusoidal waveform while second portions of said ribs remote from said free edge and closer to said cover portion are substantially V-shaped.

2. A crown cap as claimed in claim 1 wherein the parts of said skirt portion joining adjacent ones of said second portions of said ribs are substantially flat, whereby said second portions of said ribs and said parts of said skirt portion joining adjacent ones of said second portions of said ribs are shaped in a substantially rectangular waveform having inclined leading and trailing edges.

3. A crown cap as claimed in claim 1 wherein said skirt portion is'turned inwardly upon itself at said free edge.

4. A crown cap as claimed in claim 1 including a reinforcing member formed integral with each of said ribs and disposed between said second portions of said ribs and said free edge.

5. A crown cap as claimed in claim 4 wherein said reinforcing members are curved outwardly in directions parallel to and perpendicular to the longitudinal axes of the respective ones of said ribs with which said reinforcing members are formed integral.

6. A crown cap as claimed in claim 5 wherein said reinforcing members are substantially part spherical in shape.

7. A crown cap as claimed in claim 2 including a reinforcing member formed integral with each of said ribs and disposed between said second portions of said ribs and said free edge.

8. A crown cap as claimed in claim 7 wherein said reinforcing members are curved outwardly in directions parallel to and perpendicular to the longitudinal axes of the respective ones of said ribs with which said reinforcing members are formed integral.

9. A crown cap as claimed in claim 8 wherein said reinforcing members are substantially part spherical in shape.

10. A crown cap as claimed in claim 8 wherein said skirt portion is turned inwardly upon itself at said free edge.

11. In a crown cap of the type having a cover portion and a skirt portion, said skirt portion having a free edge disposed remote from said cover portion, said skirt portion also having a plurality of spaced apart outwardly extending ribs formed therein and extending from said free edge towards said cover portion, the improvement comprising a reinforcing member formed'integral with each of said ribs and disposed intermediate the ends of said ribs.

12. A crown cap as claimed in claim 11 wherein said reinforcing members are curved outwardly in directions parallel to and perpendicular to the longitudinal axes of the respective ones of said ribs with which said reinforcing members are formed integral.

13. A crown cap as claimed in claim 12 wherein said reinforcing members are substantially part spherical in shape.

14. A crown cap as claimed in claim 12 wherein said skirt portion is turned inwardly upon itself at said free edge.

References Cited UNITED STATES PATENTS GEORGE T. HALL, Primary Examiner 

